
#ifndef __UIP_PBUF_H__
#define __UIP_PBUF_H__

//#include "lwip/opt.h"
//#include "lwip/err.h"
#include "uip-conf.h"
#include "uip_etharp.h"

typedef rt_int16_t	s16_t;
typedef rt_int8_t	err_t;
#ifdef __cplusplus
extern "C" {
#endif

#define PBUF_TRANSPORT_HLEN 20
#define PBUF_IP_HLEN        20

typedef enum {
	PBUF_TRANSPORT,
	PBUF_IP,
	PBUF_LINK,
	PBUF_RAW
} pbuf_layer;

typedef enum {
	PBUF_RAM, /* pbuf data is stored in RAM */
	PBUF_ROM, /* pbuf data is stored in ROM */
	PBUF_REF, /* pbuf comes from the pbuf pool */
	PBUF_POOL /* pbuf payload refers to RAM */
} pbuf_type;


/** indicates this packet's data should be immediately passed to the application */
#define PBUF_FLAG_PUSH 0x01U
#ifdef RT_USING_LWIP
struct pbuf {
	/** next pbuf in singly linked pbuf chain */
	struct pbuf* next;

	/** pointer to the actual data in the buffer */
	void* payload;

	/**
	 * total length of this buffer and all next buffers in chain
	 * belonging to the same packet.
	 *
	 * For non-queue packet chains this is the invariant:
	 * p->tot_len == p->len + (p->next? p->next->tot_len: 0)
	 */
	u16_t tot_len;

	/** length of this buffer */
	u16_t len;

	/** pbuf_type as u8_t instead of enum to save space */
	u8_t /*pbuf_type*/ type;

	/** misc flags */
	u8_t flags;

	/**
	 * the reference count always equals the number of pointers
	 * that refer to this pbuf. This can be pointers from an application,
	 * the stack itself, or pbuf->next pointers from a chain.
	 */
	u16_t ref;

};
#else    /* RT_USING_UIP */
struct pbuf {
	/** pointer to the actual data in the buffer */
	void* payload;
	rt_uint16_t len;
};
#endif
/* Initializes the pbuf module. This call is empty for now, but may not be in future. */


struct pbuf* pbuf_alloc(pbuf_layer l, u16_t size, pbuf_type type);

u8_t pbuf_header(struct pbuf* p, s16_t header_size);

u8_t pbuf_free(struct pbuf* p);

#endif /* __UIP_PBUF_H__ */
